A well intervention, or well work, is any operation carried out on an oil or gas well during, or at the end of, its productive life that alters the state of the well or well geometry, provides well diagnostics, or manages the production of the well.

Well drilling is the process of drilling a hole in the ground for the extraction of a natural resource such as ground water, brine, natural gas, or petroleum, for the injection of a fluid from surface to a subsurface reservoir or for subsurface formations evaluation or monitoring.

A weir or low head dam is a barrier across the width of a river that alters the flow characteristics of water and usually results in a change in the height of the river level.

Weight is the force exerted on an object by gravity.

A method that can be used to present information or conduct a meeting via an online link with participants that are unable to attend a face to face meeting.

A weatherproof service drop entry point where overhead power or telephone wires enter a building, or where wires transition between overhead and underground cables.

An instrument used for showing the direction of the wind, also known as wind vane or weathercock.

A weather station is a facility, either on land or sea, with instruments and equipment for measuring atmospheric conditions to provide information for weather forecasts and to study the weather and climate.

Weather forecasting is the application of science and technology to predict the conditions of the atmosphere for a given location and time.

In physics, the wavelength is the spatial period of a periodic wave—the distance over which the wave's shape repeats.

Wave propagation is any of the ways in which waves travel.

Energy that is generated by harnessing the forces from waves.

A wave farm is a collection of machines in the same location and used for the generation of wave power electricity.

A wattmeter is an instrument for measuring the electric power in watts of any given circuit.

A machine that converts wave energy into usable mechanical energy.

Unit used for the power rating of photovoltaic installations, "one kilowatt-peak" meaning "one kilowatt of peak power".

A water wheel is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill.

In water tube boilers, water circulates in tubes heated externally by hot exhaust gas from an engine.

A rotory engine that converts water energy into power from its flow from height. Usually found in water dams.

Water resource management is the activity of planning, developing, distributing and managing the optimum use of water resources.